1. Field of Invention
The present invention relates to a system for mixing liquid within a tank or reservoir, and more specifically to three dimensional system of inlet and outlet conduits in communication with a directional flow control valve, which conduits are arranged for distribution of the liquid within the tank or reservoir to obtain mixing during filling or draining.
2. Background of the Related Art
Since the early 1990's there has been increased concern regarding the water quality in potable water storage tanks and reservoirs. Short-circuiting between influent and effluent (meaning liquid inlet and outlet conduit(s)), and/or stratification of disinfectant residual concentration, or the water itself, can cause water quality problems due to water stagnation in such potable water supplies.
The United States Environmental Protection Agency (“EPA”) regulates the potable water industry in the U.S. The EPA requires that water in tanks be completely turned over and replaced within a couple of days time to preserve and ensure water quality. Disinfectant residual levels within the water supply are also mandated by the EPA to remain above certain minimums to maintain potable water safety. Unfortunately, such measures have not been entirely successful, and water quality issues continue to be of concern for most potable water distribution systems.
During cold weather, where sufficient liquid turn over is not obtained, water within a tank may form ice. Such ice formation increases the potential for damage to the tank, as blocks of floating ice scrapes against the steel and rips protruding metal off walls of the tank. Ice damage is expensive and inconvenient to repair. Such repairs may require a water supply to be taken off line, which adds even further expense, as a substitute supply must be provided. By obtaining sufficient mixing or movement of the liquid within the tank, ice formation is minimized.
Additionally, there has also been an increased desire to obtain energy savings during the mixing of liquids in other liquid storage facilities, such as sewage, fuel or other chemical tanks or containers.